Braun tube



Dec. 31, 1940.

Fiied Sept. 21. 1934 Patented Dec. 31, 1940 UNITED STATEIS PATENT OFFIC BRAUN TUBE Bruno Wienecke, Berlin, Germany Ap1ilication Septianibgr 211934, 'Serial N0. 744,964 In Germany September 23, 1933 16 Claims. (o1. 250-155) In discharge tubes having a na rrowly conc sntrated and carefully directed discharge, as 'for example cathocie ray tubes of the Braun type,

it is an important condition that the electrodes' system at all, and the tube is wholly unserviceable.

In the construction heretofore of tube s o'f this natura the accomplishment of goqd Centering de- 20 pends to a great extent on the skil1 of the person performing the assembly. It also frequently occurs that a system carefully ass'embled, for example with the assistance of gauges, discloses neverthel ess upon the si1bsequent evacuating 25 process, in which for degassing purposes the entire dischargevessel requires to be greatly heated, errors in centering observable after this operatiqn. 'Ihis is due 110 the fact that the electrod es, by reason of stresses in -the material owing 'to the 30 heat, have become relatively deformed.

All of these erro1*s are avoided by th con struction according to my invention. 'I'his construction is also verysimple to assemble in welicentered fashion, even by unskilled persdns. In

35 principle the same is based on the fact that the diflerent electrodes possess the form f coni'cal tube portions, in each of which th'e angle b6tween the jacketline and the middle axis is the same, so that they maybe inserted firmly one 40 into the other. A total anglefof the -aperture amounting 1:0 approximately 45 has'been f0und 110 be suitable. The individual electrodes areseparated frorn each other by m aans of similarly shaped and fitting members composed of insu' 1ating material. All o1 these nested paits may then be held toge'ther by means' cf a simple tensioning devi ie, which exerts a pressusre In the direction of the longitudinalaxis. The whole then resu1ts in a structre which is s't'ab1e in it- 50 self a;nd comparatively rigid.

In this construction all metallia prts, and more particularly the cilp-likec0riical tube portions; may readily be produced in exact and identical fo1m by stamping and drawing. In the 55 same manner the insulating partsWhich-'preferabiy are composed 0f a ceramio material, are capab1e of production readily and cheaply on masssale production lines in sufficiently exact and identirzal form without special expenditure by the methods usual in the ceramic art. 5 An example of the constructicn according to the invention is illustrated in the drawing, Fig. 1 showing a longitudinal section -and Fig. 2 a cross-section in the plane AB. The drawing, Omitting the parts not pertaining to the inventio n anal more particularly the glass body, show the system of a cathode ray tube producing the ray with a pairof defiecting plates. The p'ortions of the electrodes and of the insulating Ineinbers shoWn in section are difierentiated by therespective cross-hatching or shading. The originating point of the distaharge is constituted by the hot cathode l, which may consist, for ex- 'ample of a platinum band having ab its centre a small spot 0f Wehnelt oxide substance. The 120 platinum band is secured to two leads 2 cqmposed of streng wire, which in turn are passed through two smal1 tubes 3 of in'sulaLting material. The tubes are secl1ied in holes in the cup-shaped inetallic member 4 and in a p1ate-1ike counterbearing 4 welded, for example, 150 the member 4. The tubes 3 and also the leads 2 are secuied in any suitable fashion against displacement and. rotation in their bearings, for exampleby triangular or square cross-secti0ns and by heading the metallic 1e2ids, viz. a1; the ends projectihg out of the tubes. A second cup shaped similarly to the metallic member 4 is located at 5. The same has at the center of its transverse portion an aperture, which exerts the ef1ect of the so- Called Wehnelt cylinder serving for concentrati0no'f the ray. B'etween the two cups 4 and 5 there is situated the first of the insulating memberS 6. An additio'nal, similarly shaiped insulating member is shown at L The same carries Ehe cup 40 8, Which also possesses an aperture at the narrdw end. This cup 8 constitutes the' anode Cf the systm. In the same manner, separated from each cither by the insulatirig members 9 am]. IG, there are provided two additional cups H and. I2, o'f which each carries a deflecting platze. Each plateis se( ured to its cup in such fashion that the plates in the fina1ly assembled system are situated opposite 110 each other as shown. In similar fashion it isnaturally also possible to provide still '5 furthar 'electrodes. Further, 1;he cathode Cornposed of platihum band may naturally als-o be replaced 'by one With indirct heating, and the emissive surface itself may possess a suitable form and size. The final cup 12 carries in turn tlre threaded pins I5if necessary, extended in'--' length.

5 As material for the insulating members all substances may be employed Which are valcuuiii-" proof, heat-resisting and sufficiently -non-con ductive, such as glass, quartz, mioa;poroelain;

steatite, oxides of metals or mixtures j;hereof such as aluminium oxides, for exanhple Sinter; corundum, magnesium oxide, beryllium Oxide, zirconium oxide or also powdered mica mixed with a suitable, preferably organic binding agent, and similar substances which more recently have been placed on the market under different names by the ceramic trade. It is desirable 130 employ those substances Which may be furnished With a vacuum-proof glaze. 'Ihia surfaces of theinsulating members not touohed by the metallic cups may be increased by ehe provision of grooves or the like for the purpose of increasing the surface path between the electrodes. Further, the surfaces covered by the metallic parts may also b e furnished with ribs in order to increasethe insulating value and permit of a more rapid degassing of the metallic parts and insulating members. For the purpose of clear disolosure, arib construction of this natura is illustrated in Fig. 2.

I claim: 1. A Braun taube comprising electrodes including a cathode for producing a cathode ray, an electrocle for controlling the intensity of the cathode ray, electrodes for ooncentrating the cathocle ray and electrodes having plate shaped 45 portions for defiecting the cathode ray each.of said electrodes except said cathode -having a conical portion and a pluralityof insulating elements of conical shape for insulatingsaid electrodes from one another, said conical por- 50 tions of said electrodes and said insulating elements being alternately fitted with in one another to exactly align all of said electrodes With one another.

2. A Braun tube comprising a ca thode fur- 5 nished With a metallic holder having a con ical portion, tw0 deflecting plates, each 0f said defleoting p1ates being provided with a metallic holder having a conical portion, a control electrode mounted between said cathode and said deflecting plates, ab least one anode mounted between said control electrode and said deflecting plates and insulating elements for insulating' tween said control electrode and said deflecting' plates and insulating element for insulating each two of said electrodes from one another, said control electrode, said anode and each of said insulating elements having a conical portion, all of said conical portions having the same shape, each two of said portions being fitted within one another, means for pressing all of said parts against one another and means for connecting all lof said (eleotrodes with their' respective circuits.

4. A Braun tube Cathode ray, electrodes for concentrating the cathode ray and electrodes having plate-shaped pqntions for deflecting the-cathode ray each of saidfele'ctrodes, except said cathode, having a conical portion, and a plurality of insulating elements of conical shape for insulating said electrodes from one anothersaid conical portions of.said electrodes and said insulatir'1g eleinents being alternately fitted within one another, so that said electrodes form a system of eXaotly axially aligned electrodes, two annular fittings, one of. saidfittings being secured t0 each end 0f said sys'tem of axially aligned electrodes, and pins conneoting said annular fittings with each other so hold said System together.

5} A Braun tube comprising an envelope having a glass-base, electrodes inclilding a cathode for proclug'zing a.cathode ray, an electrode for Control1ing the infinsityof thecathode ray, eleotrodes forcoricentrating the cathoderay and eleotr odkas having platze shaped portions for deflecting the cathode ray, each 0f said electrodes, except said cathode, having a coriical portion, and a plurality of insulating elements of conical shape for insulating said electrodes from one another, said conical portions of said '(2 1ectrodes andsmid insulating elements being alternately fitted Withiri one another, so that said electrodes frm a sys'tem of exactly axially alig-ned elentrodes, means for assenlbling said system to form a structuralunit, and means for securing said structural unit ajs a whole to said glass bse.

6. A Braun tube comprising an envelope having aglass-b'psta, electroclesincluding a cathode for produeing=a cathode ray, an electrode for controlling the intensity of the cathode ray, electrodes for oonoentrating the cathode ray and electrodfies having plate-shaped portions for deflecting fche cathode ray, each of said electrodes, exc pla said eathode, havinga conical portion,- and a plurality of insulating elementsof conical shape for insulatingsaid electrodes from one another, said conical portions cf said electrodes and said insulating elements being alternately fitted wilzhinone another, so that said electrodes form a system of exactly axially aligned electrodes;

two annular fittings, one 0f said fittings being secured 1:0 each end of said system of axially aligned electrodes pins connecting said annular fittings with each other 130 holdsaid system together so J;hat said System forms a structural unit, and means for securing said structural unit as a whole 130 said glass base.

7. A Braun tube comprising eleotrodes including a cathode for producing a cathode ray;an electrode for controlling the intensity ofv the cathode ray,..electrodes for concentrating the cathoderay and electrodes having plate shaped portions for-deflecting the cathode ray, each cf said electrodes, except said cathode, having a conica1 portion, and a plurality of insulating elements comprising electrodes includ- -ing a cathode for producing a cathode ray, an ..eleotrode for controlling the intensity of the of conical shape for insulating said, electroclesinto which said insulated elements are fitted being provided With recesses to increase the effective surfaces. 8. A Braun tube comprising electrodes including a cathode for producing a cathode ray, an

electr'ode for controllingthe intensity 0f the cathode ray electrodes for concentrating the cathode ray and electrodes having plate-shapecl portions for deflecting the cathode ray, each of said electrodes, except said cathode, having a conical portion, and a plurality of insulating elements of conical shape for insulating said. e1ectrodes from one another, said conica1 portions cf said elect rodes and said insulating elements being alternatly fitted within one another 120 exactl:v

align all of said electrodes with one another, the surfaces cf said insulating elements at the parts thereof in contact with ehe respective electrodes into which said insulating elements are fitted being provided withgrooves to improve the insulation between the electrodes.

9. A Braun tube comprising electrodes includfing a cathode for producing a cathode ray an eleatrode for controlling the intensity cf 1:he-

cath0de ray, electrodes for concentrating the cathode ray and electrodes having plate-shaped portions for defiecting the cathode ray, each cf said electrodes, except said cathode, having a conical portion, and a plurality of insulating elements cf conical shape for insulating said. elentrodes from one another, said conical portions of said e'lectrodes and said insulating elements being 40 alternately fitted Within one another 130 exactly align all of said electrodes with one another the surfaces of saidinsulating elements at the parts thereof in contact with the respective electrodes into which said insuIated elements are fitted be- 5 ing provided With ribs to improye the insulation between the elec trodes.

10. A Braun tube including means for produc ing electrodes having plate-shaped portions for deflecting said ray.

11. A Braun tube including means for producing a cathode ray, nested flaring electrodes for ;controlling saicl cathode ray two of said flaring electrodes having plate-shaped portions for deflecting said ray, anal fiaring insulating members interposed between the flaring faces of ne ighboring electrodes.

12. A Braun tube including miaans for producing a cathode ray, nested flaring electrodes for controlling said cathode ray, and flaring insulating members interposed between the flaring faces of neighboring flaring electrodes.

13. A Braun taube including means for producing a cathode ray, nested fiaring electrodes for controlling said cathode ray, fiaring insulating members interposed between the flaring faces of neighboring electrodes, am]. means for exerting pressure on said electrodes and insulating members hold said electrodes in contact with said members.

14. A Braun tube including means for producing a cathode ray, electrodes for controlling said ray, anal insulating members interposed between neighboring eleccrodes, the surfaces of said insulating elements being provided With a vacuumproof glaze.

15. A cathode ray tube for producing a focused beam of electrons including a source of electrons, a plurality of frustro-conical conducting electrodes, a plurality of frustro-conical insulating elements, means for positioning the electrodes as an integral part of at least two of said e1ectrodes and a1igned so asto be opposite each other and symmetrically disposed with respect to the axes of symmetry of the.electrodes.

16. A cathode ray tube for producing a focused beam of electrons including a source 0f electrons, a plurality of frustro-conical conducting electrodes, a plurality of frustroconical insulating elements, means for positioning theelectrodes and the insulating elements in alternate nested relationship with their axes of symmetry in substantial alignment, beam defiecting plates connected individually to at least two of said electrodes and positioned opposite each other and in substantially parallel planes, the plates being symmetrically disposed With respect to and arranged parallel 130 the axes of symmetry of the electrodes.

BRUNO WIENECKE. 

